March is the activity month in Paris. You can enjoy the great carnival - "Carnaval Des Femmes". You can experience little rainfall but it will be a pleasant atmosphere.
It is a peak tourist season. You can witness royal parks and gardens blossoming. Get a chance to enjoy the St. Patrick's Day festival and observe the parade.
It is said "Marzo E' Pazzo" means march is crazy. By the end of March and beginning of April, you will then enjoy the sight of flowers blooming and greenery reappearing.
If you are Honeymooners, March is the best month for you. Winter is about to end and sight seen will be a pleasurable time.